Outlook Express is a trustworthy email client that comes as a part and parcel of the Windows OS. Separate DBX files will be maintained for each personal folder which in turn stores all the emails. In a few cases, the store folder may be corrupt and you may not be able to access it. In such cases, you may encounter severe loss of data and may require the help of recovery software to get back your significant data.
The store folder may be corrupted due to its large size, compaction of files and various other reasons. Even if, the error message shows up with various reasons, which may not be the cause, in fact. The cause of this problem is file corruption, and you need to resolve this issue by using an Outlook recovery tool.
If you be desperate to immediately resolve the error message, without recovering the data, then it is very simple. Just delete or rename the corrupted dbx file and restart. It reconstructs all the lost folders, when they are not found in the Outlook express. However, this technique will not aid you to get back your lost data. If the data is very important, you are supposed to use a tool.